The 4.0 is known for ticking noises. But might as well locate where it's coming from.
Nother way to locate the sound is using a long screwdriver. Place you ear over the handle end, and touch the other end on various spots around the engine compartment, careful for moving parts.
On ours I found the distributor was the culprit. Had a dry upper bushing. Something not normal for the early versions (ours is a 97) but notorious on the later ones. And it's one of those if you don't catch it early you can easily end up with major damage.
97 Sahara, 74 Renegade, 72 CJ5, 55 Willy's (the Beast) Boss 302, 6:34 gearing, Bose 901 speakers.
God I miss that Jeep. Forgot the kinda Jeep, 80 SX4.